Let-back for take-up mechanism of looms.



I S.S.JAGKSON. LET-BACK FOR TAKE-UP MECHANISM OF LOOMS. APPLICATION FILED FEB.27, 1913.

1,079,29 r I 'PatentedN0v.18,1913.

Zflnesses:

COLUMBIA PLANOGRAPH 60.. WASHINGTON. D. c.

TTNTTED BTATES PATENT OFFICE.

SIMEON S. JACKSON, 0F BOSTON, MASSACHUSETTS ASSIGNOR TO THE STAFFORD COMPANY, OF READVILLE, BOSTON; MASSACHUSETTS, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Nov. 18, 1913.

Application filed February 27, 1913. Serial No. 750,939.

To all whom it may concern:

Be it known that I, SIMEoN S. JACKSON, a subject of Great Britain, residing at Readville, Boston, in the county of Suffolk, State of Massachusetts, have invented a certain new and useful Improvement in Let-Backs for Take-Up Mechanism of Looms, of which the following is a specification, reference being had therein to the accompanying drawing. T

The invention consists in means for insuring engagement of the let-back dog or pawl of a loom take-up mechanism with the toothed wheel with which it cooperates, and thereby securing proper control of the extent of the letting-back.

The invention is designed to insure promptness and certainty in the engagement of the said dog with the said teeth.

The drawing shows in side elevation a portion of the frame of a loom, and certain portions of the take-up: mechanism of a loom, including let-back devices having the invention applied thereto.

Having reference to the drawing,1 is the loom-frame, 2 the actuating worm-shaft of the takeup mechanism, 8 the take-up worm, and 4 the worm-gear of the take-up mechanism. The said wormgear is actuated as usual through the rotation of the worm-shaft and worm, to effect the taking The drawing shows well-known means for lifting the worm out of engagement with the worm-wheel under the control of the weft-detector devices of the loom, for the purpose of disconnecting the taking-up temporarily when such devices act, as, for instance, in case of weft failure or breakage. Such means comprises the usual transverse shaft 5 mounted in bearings at the front of the loom-frame just below the breast-beam and rocked at times in the working of the loom through the agency of the weft-detector mechanism, the arm 6 fixed upon the said transverse shaft at one end of the latter, the connecting-link 7 having its upper end connected pivotally with said arm, and the collar 8 surrounding the worm-shaft just in front of the worm and having the lower end of the said connecting-link pivotally connected thereto. When the transverse shaft is rocked under the control of the weft-detector mechanism in wellknown manner, such rocking of the said shaft serves, through the arm, connectinglink, and collar to lift the worm-shaft so as to disengage the worm from the teeth of the worm-gear, thereby arresting the taking-up action and permitting the take-up mechanism to let back.

7 A well-known form of let-back dog is represented at 9. It is pivoted at 10 upon a fixed stand 11 in connection with the loomframe, and furnished with teeth for engagement with those of the worm-gear. When the worm-gear is rotated forwardly in the regular taking-up operation, the teeth of the worm-gear act upon those of the let-back dog to swing the latter out of the way, so that the dog does not interfere with the forward turning movement of the worm-gear. When the worm-shaft and worm-gear are moved so as to disengage the worm from the worm-gear, the backward turning movement of the worm-gear which takes place as a part of the letting-back movement causes the teeth of the worm-gear to engage with those of the let-back dog so as to rock the said dog backward until a stop-proj ection 9 upon the dog brings up against the acting end of an adjusting screw 12 fitted to a threaded opening tapped in the lug 13 of the stand supporting the dog. This contact of the stop of the dog with the adjusting screw arrests the backward turning movement of the dog, and thereby determines the extent of the letting-backmovement of the take-up mechanism as will be understood. A second adjusting screw 14 applied to another lug 15 of the said stand limits the extent of the movement to which the let-back dog can swing forward under the action of the teeth of the forwardly rotating worm-gear, and causes such dog to remain in position close 'to the teeth of the worm-gear during the regular working, 1n readiness to engage quickly therewith in case of letting-back movement and consequent backward turning of v the sa1d worm -gear:

With-therear tooth of thelet-back-dog in contact with the point of one of the teeth of the worm-gear at the moment at which the worm *is" lifted r out of mesh with the wormgear it might happen, and sometimes has happened in practiceythat a= sudden-- recoil or backward turning movement of the wormgear, especially if taken; in connection with I a sluggish movement of, the let-back dog into engaging position, would cause a number of the teeth of the worm-gear. to pass the-let b'acli dog priorto'engagementofthe let-hack dog with the teeth of t Wormge'ar. This-means an excessive letting-back; V

and-unless discovered by; the weaver" and corrected" or: eompens'atedforby him, prior to the continuation of the weaving "operation-,1

woul'di result thick. place in -the cloth being woven, and consequently in a' defect in" such *cloth.' h g I For the purpose of preventing; the improper action to" which reference has j ust" been made, and? the production of thick places thereby, I proviclefmeansfor"definite or jpositivepso'to speak, actuation off' the" let back cl'oggintoengagementfwith the teeth of thez'worm gear at the time ofi.the' lifting" of'the worm'out'oflmesh with the'worni-gear'..

Thesaididevices comprise a link 18' fas-' connectinglinlil "aforesaid, and acontractingl'sp-iral spring2O having one end thereof engaged'with the said link 18'; and theother end thereofengage'd with 1 a'h'eaded' pin" or gatedloop' receiving the stem of the pinior. screw 21 Th'e'combijned lengthilofthelink' 18, the springin" its contracted an'd relaxed l state, and "the said loop; is such that so long as the arm 6 i and connectln'g yllnli 7' i are 'in their normal lowered, position with w'orm- 3 in mesh'with w'orm;geari4 the let-back dog "is permitted suflicient amount "of play toi'permit successive teeth "of the worm-gear' to; first contact withthe' rear tooth. of the dog and' theI1- pass such tooth, preferably without bringing thettension of the spring into play. To provide for a proper setting of 'thedower 'end" of the link of the" spring with relation" to the pin orscrew 21" of the Iet b'acIr' dog, thelink"18 is formed with a longitudinal slot 18 receiving the stem of the bolt or:clam'p-screw119i This enables the linklSto headjusted up ordown with reference to theeonneetiirg-liirlf'? so as todispose'*-'the"lower end "oftheelongated 100 The" other end of the spring properly with relation to pin or screw 21 of the let-back dog.

Heretofore the let-back-dog has been held inreadiness for engagement with the coperating toothed wheel in what may be termed a". purely negative manner, namely by gravity. My invention is characterized by providing for positive action, but in yielding manner, in causing the engage- ;mentof the let-back dog with the said wheel. What is claimedas the invention is,

1.- In take-up mechanism for looms, the combination with letting-back devices including a let-back dog" which cooperates with a wheelto control the extent of lettingback, of means for definite or positive actuation of said dog "into engagement with said wheelat time ofletting-bac 2. The combination with take-up mechanism includingyawheel, and a let-backdog which cooperateswith' said wheel, oflet ting-back: means operating to release said wheel for letting-back purposes, and a spring "through which the movement of "said letting-'haclc'means"to occasion letting-back produces actuation of the-said dog into engagement with the wheel 'to limit the extent 1 of letting-back} 3. In take-up mechanismthe combination with take-up 1 gearing, letting-back devices 'opera-ting to disconnect such gearing for ther-le'tting-back, and a let-back dog that cooperates with a rotatable wheel, of a spring through which the movement' of'said dev1ces to disconnect the gearing actuatesthe said-dog mto engagementwith the said wheel to control theextent ofthe letting back; I p g 4. In combination,- vtakeup mechanism including'a worm-drive, letting-back devices operating to operatively disconnect said drive for thelettiirgbach, and a let-back dog" that cooperates with" a wheel of said mechanism, of" means through which the movement of said devices to disconnect said drive *actu'ates' the said dog into engagement with the said'wheel to control-the extentof' the letting back.

5Q Incombination, take-up mechanism ineluding a worm and worm-gear, lettingback devices whereby said'worm is disengaged from said worm-gear for letting-back purposes, and means through which the movement of 'said devices to disengage said worm actuatesithe do'g' into engagement with saidworm-gear to limit the extent ofthe letting-"hack.

6. In combination, atak'empworm and gear, arlet-baclidogwhichcooperates 'with said gear, a tin nsverse shaft, and means con nected therewith forlifting said worm *out of mesh with the" wheel driven therebyand i also directly actuating said dog into engagethrough which the arm actuates the said 10 ment with the gear with which it cooperdog into engagement with the worm-gear. ates. In testimony whereof I afiix my signature 7. In combinatlionl, a1 takel-lup worm and in presence of two witnesses.

worm-gear, a letac: 0g w ich cooperates with said worm-gear, a transverse shaft SIMEON JACKSON provided with an arm, means in connection with said arm for lifting said worm out of mesh With the worm-gear, and a spring Witnesses:

NATHAN B. DAY, CHAS. F. RANDALL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patentl,

. Washington, D. 0. 

